A worker from the Davey Tree Expert Co. injects an insecticide into the soil around an ash tree in Elgin in mid-June as part of the city's partnership with the Valent USA Corp.'s Tree Legacy Program.

Courtesy of Valent USA

The ash borer gets under the bark of the ash tree and over time forms the curvy lines called a gallery. When several of these galleries connect, they keep the tree from producing sap and the tree slowly begins to die, according to tree experts.

Several suburbs will receive insecticide from Valent USA Corp. for each of the next five years to treat ash trees infested or at risk of being infested with the emerald ash borer to see whether more trees can be saved rather than cut down. Here's a look at how many trees each town treated this year and how many have had to be cut down since the green pest hit the suburbs.

Town: Treated/Chopped down

Elgin: 210/30*

Glen Ellyn: 208/284

Naperville: 200/At least 400

Schaumburg: 198/20

St. Charles: 200/575*

Note: does not include ash trees cut down because of age or structure

* Estimated

Source: Valent USA Corp., Daily Herald interviews

Once the emerald ash borer invades a tree, it's time to break out the chain saw.

Or is it?

A Walnut Creek, Calif.-based company is working with several suburban towns in an effort to treat infected ashes with an insecticide that kills the larvae before they can dig tunnels into the tree's trunk.

The Illinois Department of Agriculture doesn't endorse a specific product or method for treating infected ash trees, but Juliann Heminghous, the department's emerald ash borer outreach coordinator, says municipalities -- many of which face their own budget woes -- are doing what they can to be proactive in fighting the bug.

"Communities are looking for better ways of dealing with the emerald ash borer infestation rather than allowing their canopies be completely removed like they were with Dutch Elm (Disease) and American Chestnut (blight)," she said.

The company that is working with suburban towns, Valent USA Corp., has dubbed the program the Legacy Tree Project and doled out about $52,000 total to Elgin, Glen Ellyn, Naperville, Schaumburg and St. Charles to treat ash trees. Unlike Elgin, however, St. Charles opted to apply the insecticide on its own.

Valent has pledged to continue the funding for once-a-year treatments, which consist of injecting an insecticide into the soil around an ash tree's roots, for a total of five years.

If the treatments work, it could be a win for cash-strapped cities and a feather in the cap for Valent with a proven test area right here in the suburbs.

"(Cities) are probably trying to manage their pocketbooks with the treatment plan. It's going to cost them no matter what they do, whether they treat a tree or remove it," Heminghous said. "This will give them time to allow them to budget their resources."

Joe Chamberlin, a field development manager for Valent, said the aim is to increase awareness among residents.

"It's not a death sentence (for the tree if it's infested with emerald ash borer). That's how it was when it first got here," he said.

Some studies have estimated the ash borer could do some $10.7 billion worth of damage across the country in the next 10 years. Insecticides are not a cure-all, especially if a tree is in advanced stages, but can be helpful in fending off an early infestation or protecting at-risk ash trees.

"You hear the term 'endangered species' all the time. We have an endangered genus, which is the next step up from a species," Chamberlin said, stressing early detection is key. "We're really just in the upslope of that right now. This is going to become much, much worse."

The Lisle-base Morton Arboretum prefers not to endorse specific products and methods to treat trees infested by the emerald ash borer. Its website, mortonarb.org, says that research suggests insecticides may be more effective if overall tree health is maintained - and the best long-term defense is a diverse tree population.

Tchukki Andersen, a staff arborist for the New Hampshire-based Tree Care Industry Association, said that as the ash borer spreads, municipalities in general are looking for alternatives to the chain saw for their tree stocks.

"Now that the emerald ash borer is moving into new areas, we have a better toolbox, so to speak," she said. "We'd rather treat trees than remove them because replacing them is impossible.

The insecticide used by Valent is applied by injecting it into the soil around the roots. Chamberlin said the insecticide kills the larvae after they hatch and begin burrowing into the trunk.

The insecticide also makes the leaves poisonous to adult emerald ash borers, killing them so they can't lay eggs, he said.

Cutting down an ash tree can be costly on several fronts, Andersen says.

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"When you remove a tree, money is coming off the property in droves," she said.

Removing a large ash tree can cost a homeowner more than $1,000.

Mature trees enhance property values while providing shade that reduces the cooling costs for a home.

Some treatments involve licensed professionals who drill holes in a trunk and inject the insecticide directly into the tree, but those can cost at least $100 a year.

Chamberlin also said insecticides can be bought over the counter at hardware stores and usually cost about $20 a year for a tree with that has a trunk 12 inches in diameter. The larger the tree, the more insecticide it needs.

Application under the Tree Legacy program is being handled by Davey Tree Experts.

Chamberlin said it is frustrating to know that thousands of ash trees might needlessly meet the ax because homeowners don't know all their options.

"The overall purpose is to use the municipal ash tree as an example of what can be done for residents," Chamberlin said. "So many people, they just don't think there's anything they can do. You only get one chance to get it right."

The green beetle invaded Glen Ellyn in 2009 and the village spends about $10,000 on treating some 200 trees a year out of the 1,900 ash trees in town, said Glen Ellyn Public Works Director Joe Caracci.

The grant from Valent allowed the village to treat an additional 200 that would not have been treated before, Caracci said.

The emerald ash borer hit south Naperville in June 2008 and gradually spread north, said Patti Sauntry, the city's assistant forester.

Crews applied to insecticide to trees in the Iroquois subdivision on the city's north side after at least 400 ash trees were cut down, she said.

"Since then, it's just been popping up all over the place," Sauntry said. "We've been cutting down so many (ash trees) lately."

Schaumburg Public Works Director Steve Wienstock said crews applied the insecticide to trees on Syracuse Lane, west of Springinsguth Road, and in the Spring Cove subdivision.

Elgin leaders have contracted with Davey to apply the insecticide and have bolstered the donation from Valent with additional funding.

"This is private funding that came to the city. People do have an option other than just cutting ash trees down," said Jim Bell, Elgin's superintendent of parks, who noted trees must be diagnosed and treated early on. "Once the damage is severe, there is no recovery for the tree."

Elgin plans to spend about $20,000 a year on treating ash trees and will evaluate what to do after the Valent program expires.

Brian Borkowicz, manager for the Davey Chicago office, said an estimated 30 trees have been cut down in Elgin directly because of emerald ask borer. While that number seems low, Borkowicz said the real mission is protecting the city's 6,700 ash trees within its borders.

"Hopefully, we'll have funding to continue the program at that time. That's five years down the road. It gives us time to plan and budget," Bell said.

In St. Charles, city crews applied the insecticide to ash trees - young, old, infected and healthy - scattered across the city.

"It's a brand new program for us," said Peter Suhr, St. Charles public service manager. "We really want to try and utilize the program as a test for us to see how it reacts to emerald ash borer in all conditions. We're trying everything. I think we've got a pretty balanced approach to how we handle this."